I have an app using spring 3.0.3 . all needed jar have been added but when I run it in eclipse this error happen:
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

I opened the org.springframework.web-sources-3.0.3.RELEASE.jar and I can see the ContextLoader.java file!!!!
here is the web.xml configurations:

How are you running your app? If using tomcat then make sure the required jars are present on either tomcat's lib folder or create a directory called lib in WEB-INF directory and put all the spring jar's inside that.

Placing the jars on classpath is ok for development in eclipse but for running the app your container (tomcat etc) should know about it and the only way to do that is to place jars in lib directory.